Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/48—Moulds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D1/00—Containers having bodies formed in one piece, e.g. by casting metallic material, by moulding plastics, by blowing vitreous material, by throwing ceramic material, by moulding pulped fibrous material, by deep-drawing operations performed on sheet material
  • B65D1/02—Bottles or similar containers with necks or like restricted apertures, designed for pouring contents
  • B65D1/0223—Bottles or similar containers with necks or like restricted apertures, designed for pouring contents characterised by shape
  • B65D1/0261—Bottom construction
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/48—Moulds
  • B29C2049/4879—Moulds characterised by mould configurations
  • B29C2049/4892—Mould halves consisting of an independent main and bottom part
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/08—Biaxial stretching during blow-moulding
  • B29C49/10—Biaxial stretching during blow-moulding using mechanical means for prestretching
  • B29C49/12—Stretching rods
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2067/00—Use of polyesters or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/712—Containers; Packaging elements or accessories, Packages
  • B29L2031/7158—Bottles

Definitions

• the present invention relates generally to the field of manufacture, by blow molding or stretch-blow molding, of containers, in particular bottles, made of thermoplastic material such as PET.
• the invention relates to improvements made in the design of a mold base for a mold for manufacturing, by blow-molding or stretch-blow molding, containers, in particular bottles, made of a thermoplastic material such as PET, said containers having a body and having a bottom of the so-called petaloid type with five feet which are angularly distributed equidistantly, which extend approximately parallel to the axis of the container and which are separated from each other by radiating valleys at full depth convex curvilinear radial, which bottom of the container is connected to the body of the container by a substantially cylindrical connecting zone of revolution having a diameter ⁇ of about 85 to 95 mm, said mold base having, for molding the aforesaid bottom containers, five cavities that are angularly distributed equidistantly, which extend approximately parallel to the axis of the mold bottom and which are separated from each other by radiating ridge with concave extension crest, the bottoms of said cavities being distributed over a substantially circular contour having a base diameter D of
• dorsal is meant a projecting portion, elongated substantially radially, of bottom of mold which leads, in the bottom of the molded container, to the formation of a susdite “valley” separating two consecutive feet.
• the part of the containers which is the most delicate to manufacture is the bottom. It is indeed the bottom that supports the weight of the liquid column contained in the container and, in the case where it has insufficient mechanical strength, it loses its shape and the container can no longer rest stably on a support .
• the bottom precisely so that it can have the desired strength, has a sensitive wall thickness, proportionally greater than that of the rest of the container. As a result, it requires, relatively speaking, more material than the container body whose wall currently reaches a very small thickness that becomes difficult to reduce.
• the bottom therefore constitutes the part of the container in which reductions in thickness, and therefore savings in thermoplastic material, can still be envisaged,
• the bottom constitutes the region of the container whose correct forming by the blow-molding or stretch-blow molding operation is the most difficult to achieve, because the substantially larger thickness of material leads to a further stretching. slow and less easy to take.
• the bottom generally has a complex shape, or very complex, with many reliefs hollow and protruding whose correct conformation leads to the desired strength.
• thermoplastic containers are constantly seeking to improve the economic conditions of production, by attempting to produce containers requiring a smaller amount of thermoplastic material, and with ever increasing production rates.
• the object of the invention is precisely to meet these expectations of the practice and to propose an improved technical solution concerning the manufacture of the bottom of the containers, which is capable of leading to significant savings in raw material at the same time as to an increase in sensitive rate of production.
• the invention proposes a mold base for a mold of manufacture, by blowing or stretch-blow molding, containers, especially bottles, of thermoplastic material such as PET, as mentioned in the preamble, which mold bottom is characterized, being arranged in accordance with the invention, by the combination of the provisions which follow:
• each cavity adapted to form a bearing surface of a foot of the container, has a width 1., considered parallel to the periphery, between about 1.5 and 3.5 mm;
• each dorsal has a dorsal crest radius r which is between about 2 and 5 mm;
• each dorsal has flanks which are concave in an approximately axial direction and whose original tangent planes form an angle ⁇ of between approximately 52 ° and 88 °;
• the backbone H is between about 16.5 and 18 mm.
• dorsal height H is meant the height of the ridge of the dorsal above the contour having the aforementioned base diameter D.
• flanks of the dorsals are further concave in the radial direction, so that the valley flanks of the container bottoms obtained with this mold bottom are curved three-dimensionally.
• the ridges of the dorsal fins of substantially concave radial extent extend over a surface of revolution with a cross-section substantially in a basket handle, in particular a substantially oval loop.
• the height of backbone H is substantially reduced compared to what would be the dorsal height in the case where the ridges of the dorsal leaning on a hemispherical surface.
• a width 1_ of the bottoms of the cavities as low as 1.5 to 3.5 mm is certainly against the conventionally adopted solution of a cavity bottom width more substantial, typically at least 6 mm: large cavities facilitate the evacuation of air trapped between the wall of the mold and the wall of the foot of the container being blown, which allows the wall of thermoplastic material in progress deformation to effectively reach the wall of the mold and thus to obtain a container having properly shaped feet.
• the invention associates with the reduction in width of the bottom of the cavities a reduced backbone height between about 16.5 and 18 mm, compared with a height greater than 18 mm in a conventional mold: the deformation of the thermoplastic material made of a more difficult side in the bottoms of the cavities due to the smaller width of said bottoms is, moreover, facilitated at the ridges due to the lower backbone height.
• the concave shape of the dorsal flanks and the very open angle of 52 ° to 88 ° are also favorably favored, compared with an angle of about 49 ° in the current conformations of the dorsal flanks.
• a mold base arranged according to the invention resides in a container bottom molded more accurately and is able to better withstand pressure and heat.
• a typical embodiment corresponds to the combination of the following values:
• the cavities have a radius Rg_ of between about 5 and 10 mm, and preferably about 8.5 mm.
• a container bottom made using a mold having a mold bottom according to the invention has a developed surface slightly lower than that of a traditional container bottom, resulting in a reduction in volume, and therefore the weight of material which, although restricted (typically of the order of 2% by weight), does not is not less real.
• the invention proposes a molding device for the manufacture, by blow-molding or stretch-blow molding, of containers, in particular bottles, made of a thermoplastic material such as PET, said containers having a body and having a bottom of the so-called petaloid type with five feet which are angularly distributed equidistantly, which extend approximately parallel to the axis of the vessel and which are separated from each other by radially curvilinear valleys of convex curvilinear radial extent, which bottom of the container is connected to the body of the container by a substantially cylindrical connection zone of revolution having a diameter ⁇ of about 85 to 95 mm, which molding device comprises at least one mold consisting of at least three parts including a mold base comprising, for the molding of the aforesaid bottom of the containers, five cavities which are angularly distributed equidistantly, which extend approximately parallel to the axis of the bottom of the mold and which are separated from each other by concave crest radiating ridges
• FIG. 1 is a view from above of a blow mold or stretch-blow mold bottom arranged in accordance with the invention
• FIG. 2 is a diametral sectional view along the line II-II of Figure 1;
• FIG. 3 is a top view in section along the line III-III of Figure 2;
• Figure 4 is a sectional view along line IV-IV of a portion of the mold base of Figure 1;
• Figure 5 is a three quarter perspective view from above of the mold bottom of Figures 1 to 5;
• FIG. 6 is an isometric perspective view of three quarters from below a container bottom made using the mold bottom of Figures 1 to 5.
• the containers 2 to be manufactured with this mold have a body 3 and have a bottom 4 of the so-called petaloid type having five protrusions forming feet 5, which are angularly distributed equidistantly, which extend approximately in parallel to the axis 6 of the container and which are separated from each other by valleys 7 radiating bottom 8 convex curvilinear radial extent. All the valleys 7 converge at the center of the bottom which is constituted in the form of a plate 10 in slight external projection.
• the bottom 4 of the container is connected to the body 3 of the container by a zone 9 of substantially cylindrical connection of revolution having a diameter ⁇ of about 85 to 95 mm.
• the bottom 1 of the mold comprises, for the molding of the aforesaid bottom 4 of the containers 2, cavities 11 (for the formation of the bottom legs of the receptacles) in a number equal to five, which are angularly distributed equidistantly (mutual angular spacing of 72 °), which extend approximately parallel to the axis 12 of the bottom 1 of the mold and which are separated from each other by radiating ridges 13 (i.e. said protruding portions, substantially radially elongated, of the mold base which lead, in the bottom of the molded container, to the formation of the aforesaid valleys).
• Each dorsal 13 has a crest 14 of concave extent.
• the bottoms 15 of the cavities 11 are distributed over a contour 16 substantially circular having a given base diameter D of between about 60 and 66 mm, this diameter corresponding to the diameter of the base of the bottom 4 of the containers (diameter of the circular contour on which are distributed the zones of the feet 5 by which the containers are based on a flat support).
• the bottom 1 of the mold is arranged to present the combination of the following provisions:
• each cavity 11 adapted to form a bearing surface of a foot 5 of the container 2 has a width 1, considered parallel to the periphery, between about 1.5 and 3.5 mm;
• each dorsal 13 has a dorsal ridge radius r which is between about 2 and 5 mm;
• each dorsal 13 has flanks 17 which are concave in an approximately axial direction (that is to say in a substantially straight sectional plane as illustrated in FIG. 4) and whose planes tangent to the origin (c ') that is to say at the location where the rounding of the peak 14) forms between them an angle ⁇ of between approximately 52 ° and 88 °; and
• the height of the backbone H (height of the peak 14 vertically above the contour 16 of diameter D on which the bottoms 15 of the cavities 11 are distributed, as illustrated in FIG. 2) is between approximately 16.5 and 18 mm .
• flanks 17 of the dorsals 13 are concave in the radial direction, so that the corresponding valley flanks of the container bottoms are convexly convex. tridiraensionally, that is to say both radially and vertically, which increases their resistance.
• the lowering of the backbone height H can be obtained in a simple way by providing that the ridges 14 of the ridges 13 extend over a surface of revolution of cross-section substantially in a basket handle, as can be seen in the representation of FIG. left half of the mold bottom 1 given in Figure 2.
• the exact shape of this surface of revolution has no significant influence insofar as the reduction in height H is significant.
• a surface of revolution whose cross section is of simple geometric construction, such as an ellipse or, as illustrated in Figure 2, an oval of large radius R1 and small extreme radius R2.
• the cavities have a radius Rg_ of between about 5 and 10 mm, so that the corresponding feet of the bottoms of containers are substantially thinner than those of the previous bottoms.
• the arrangements according to the invention find a particularly preferred application in a molding device for the manufacture, by blow-molding or stretch-blow molding, of containers 2, in particular bottles, made of a thermoplastic material such as PET, said containers 2 having a body 3 and having a bottom 4 of the so-called petaloid type with five feet 5 which are angularly distributed equidistantly, which extend approximately parallel to the axis 6 of the container 2 and which are separated from each other by radiating valleys 8 at the bottom of convex curvilinear radial extent, which bottom 4 of the container is connected to the body 3 of the container by a zone 9 of substantially cylindrical connection of revolution having a diameter ⁇ of about 85 to 95 mm, which molding device comprises at least a mold consisting of at least three parts including a bottom 1 of mold comprising, for molding the aforesaid bottom 4 of the containers 2, ci n

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Ceramic Engineering (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)
• Containers Having Bodies Formed In One Piece (AREA)
• Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
• Laminated Bodies (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=36676067

Family Applications (1)

Country Status (9)

Families Citing this family (9)

Citations (11)

Family Cites Families (6)

• 2005
  • 2005-10-17 FR FR0510561A patent/FR2892048B1/fr not_active Expired - Fee Related
• 2006
  • 2006-10-13 CN CN2006800376827A patent/CN101282881B/zh not_active Expired - Fee Related
  • 2006-10-13 JP JP2008535065A patent/JP2009511303A/ja active Pending
  • 2006-10-13 EP EP06820211A patent/EP1945518B1/de not_active Not-in-force
  • 2006-10-13 ES ES06820211T patent/ES2364181T3/es active Active
  • 2006-10-13 AT AT06820211T patent/ATE504502T1/de not_active IP Right Cessation
  • 2006-10-13 WO PCT/FR2006/002312 patent/WO2007045749A1/fr active Application Filing
  • 2006-10-13 DE DE602006021214T patent/DE602006021214D1/de active Active
  • 2006-10-13 US US11/992,789 patent/US7891968B2/en not_active Expired - Fee Related

Patent Citations (11)

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